Public switched telephone networks (PSTNs) and other circuit-switched networks have been used to support telephony service related transmissions, such as but not limited those associated with supporting voice, video, facsimile, and data services. New networks and communications standards have been developed to support similar services, and in some cases additional services, through packet-switched operations. Networks used for circuit-switched communications may be referred to as circuit-switched networks while networks used for packet-switched communication may be referred to as packet-switched networks. The same networks may, in some cases, be used to support circuit and packet-switched communications.
A soft switch, cable modem, embedded enterprise SIP gateway (ESG), public branch exchange (PBX), or other device, collectively referred interchangeably herein as a gateway, may be used to facilitate signal conversions, protocol translations, and other operations necessary to exchange telephony and non-telephony signaling between endpoints where one endpoint is connected to a circuit-switched network and the other endpoint is connected to a packet switched network. Such a gateway may also be used to support signaling between similar packet or circuit switched networks, such as when one of the endpoints is connected to a private network or branch where all communications to that endpoint are serviced through the gateway.